Dr. Michael Pugia - Mini-laboratory on a Chip
Diagnostic tests that today are performed in large labs will in the future increasingly be performed right on hospital wards, in medical practices, pharmacies, or even in patients’ homes. This will be possible thanks to lab diagnostics that can be conducted in the patient’s presence, known as “point of care” testing (POCT): All lab processes will then be found – on a miniaturized scale – on a single chip. Michael Pugia of Siemens Healthcare Diagnostics in Elkhart, U.S., has been conducting research for years to find a way to put a growing number of functions on this lab-on-a-chip.
Many of Pugia’s 203 inventions, which have yielded 140 individual patents and 60 patent families, are in the area of microdiagnostic systems. A lab-on-a-chip contains all needed substances and reagents in dry and liquid form, as well as measuring instruments and signal transmitters for the results. “The problem is that the sample, for instance of blood or urine, is only the size of a tiny droplet,” Pugia explains. Using this much smaller quantity, the findings must be every bit as accurate as those provided by tests in main laboratories, which have entire test tubes of the samples at their disposal. “So to measure the signals, we need highly sensitive methods,” says Pugia, who is a chemist by profession.
Like many inventors, Pugia is sometimes able to progress with his work by assimilating well-established principles with adjustments to suit his purposes. Three years ago he was searching for a way to measure the sample with maximum precision and inject it into the chip. “I came up with the idea of adapting methods we see in inkjet printers,” Pugia recalls. Not only did it work unexpectedly well; it also proved to be very inexpensive because the injection device can be re-used repeatedly.
Pugia is currently working on optimizing the processes on the lab-on-a-chip. This involves arranging a system of hair-fine channels, chambers, and ventilation slits on plastic in such a way that the injected liquid distributes itself at the right speed. In various chambers the liquid mixes with the dry or liquid reagents that have been deposited there. The field of microfluidics is a relatively new branch of research. In very tiny spaces, liquids and gases behave differently than they do on larger scales. Pugia is researching the characteristic physical features and applying them in his prototypes. “Our goal is to be able to use a small hand-held instrument to perform all diagnoses that until now have been done in full-scale labs,” says Pugia. And the vision also calls for these instruments to be affordable. This opens up entirely new possibilities in medical care, for instance in remote locations.
What’s more, the new mini-laboratories should be usable by anyone. That saves not only money, but also lots of time. For example, it provides doctors in emergency cases with much faster access to test results, allowing them to make decisions more quickly concerning patient treatment.
Pugia has been working at Siemens for 23 years in basic research, focusing on clinical biochemistry, physical, organic, and inorganic chemistry, as well as in product development. He also has had several teaching appointments at universities in the U.S.